Portsdown Main is an enormous art deco styled building on the north Portsmouth skyline and is known locally as Portsdown Main or ASWE. The site was designed in the 1930sbut was not built until the 1950s because of WW2. It has been known as)
Admiralty Signals Establishment (ASE)
Admiralty Surface Weapons Establishment (ASWE)
Defence Evaluation and Research Agency (DERA)
Defence Research Agency (DRA))
Portsdown Main finally closed on 1 January 1997 and although there have been a number of Government departments interested in the site none have any plans to move there. Not much is known about the work that went on at Portsdown Main due to the secret nature of it over the years; so available history of the site is few and far between.